THE NEPTICULIDES. 175 



motionless in the mine. On the 21st the mouth had regained its 

 former brownish colour, and the larva now moved its head about in 

 a languid manner in search of food, of which it partook sparingly. 

 On the 22nd the darkish blotch had reappeared on the back of the 

 head of the larva, the old skin in the meanwhile having shrunk still lower 

 down ; the anterior portion of the body had now become much stouter, 

 and had a more healthy and fresher appearance ; the larva now com- 

 menced feeding with great eagerness ; at this period the dorsal vessel, 

 which had lately become more distinct at the fore and after part of 

 the larva's body, was quite hidden in the centre. On the 23rd the 

 whole of the dorsal vessel was distinctly visible, the anterior portion 

 being of a much brighter green than the posterior." 



Heinemann states that whilst observing the larvae of N. splendidis- 

 simella, N. angulifasciella, N. rubivora and N. ? trimaculella, in the 

 act of moulting, he was much astonished at the appearance of an 

 extraordinary series of regular oblique, quadrangular, dark, dorsal 

 spots, which gave the larva an appearance as if it were decayed and 

 spotted. These spots appeared at the moult and disappeared at its 

 completion. He says : "As the larva gradually crept out of its old 

 skin these spots remained in their place, and the pale green or pale 

 yellow larva, which had assumed a fresh colour, no longer showed 

 any trace of them. More frequently the spots moved, as well as the 

 old head, a short distance forward with the larva, but the row did not 

 always remain complete, and no longer so decidedly along the back 

 of the larva ; but as the latter, in eating, turned to the side, and 

 so took up a curved position, the green dorsal line in N. angulifasciella 

 and N. rubivora was perceptibly on the side of the row of spots. 

 Later these spots became lost in the excrement track. Hence it 

 appears that the larva assumes these spots during the moulting, that 

 these are on the old skin, which it is on the point of casting off, and 

 that in the narrow mine of the larva the old skin is drawn forward for 

 a short distance." Itis very doubtful whether Heinemann's statement 

 that the spots of these larvae appeared at this moult is correct. It is well 

 known that the larvae of the members of the angulifasciella group have 

 these dark ventral markings previous to the last moult, and that they are 

 then lost. Wood says : — " The large square-shaped spots are surface 

 markings, though, to be strictly accurate, they are rather transversely 

 oblong, with the corners rounded, than square -shaped. Their size 

 and deep black colour make them extremely conspicuous, but, curious 

 to say, they disappear with the last moult from all the segments save the 

 prothorax Both in their general appearance and in the circum- 

 stance of being limited to the middle life of the larva (I should add 

 that they are not present from the first), they remind one of the 

 ventral spots in some of the Micropterygids. Comparatively few 

 species, however, seem to possess them. The only ones I know of are 

 the members of the angulifasciella group, subbimaculella, argentipedella, 

 and, I think, quinquella" (Ent. Mo. Mag., xxx., p. 44). This would 

 suggest that Heinemann, though correctly observing the disappear- 

 ance of the marks, was in error in supposing them to have become 

 visible only at the commencement of moulting. 



The moulting of the Nepticulid larva was worked out at length 

 by Wood, chiefly by observation of the caterpillar of N. angulifasciella. 

 By a combination of different expedients narrated (Ent. Mo. Mag., 



